


No Stone Unturned

by fireflyhwufanficwriter



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: F/M, Friendship, Gen, Romance, See chapter notes for author replies to reader comments, Slow Burn
Language: English
Status: In-Progress
Published: 2020-07-01
Updated: 2021-01-17
Packaged: 2021-03-05 00:46:47
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 15
Words: 13,867
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25015681
Author URL: https://archiveofourown.org/users/fireflyhwufanficwriter/pseuds/fireflyhwufanficwriter
Summary: ---"Taking me to Ishigami Village, getting out Byakuya's glass record…" Senku spoke some more, then paused. "You're always the one doing it, aren't you?"(Senku/Kohaku.) How did the scientist fall in love with the lioness? A friendship- and science-focused retelling of Dr. Stone from Senku's perspective.(See chapter notes for author replies to reader comments :D)---
Relationships: Ishigami Senkuu & Asagiri Gen, Ishigami Senkuu & Chrome, Ishigami Senkuu & Kohaku, Ishigami Senkuu & Ruri, Ishigami Senkuu/Kohaku
Comments: 18
Kudos: 49





	1. Ruri

**Notes for the Chapter:**

> DISCLAIMER: I do not own Dr. Stone! :)

**Chapter One: Ruri**

"…Shall we go to the banquet, then? With everybody."

Ruri and the rest of the group descended the tower together, chatting about the mysterious one hundredth tale that had been waiting for three thousand seven hundred years to be told. As Kohaku, Chrome, and Suika made their way to the bonfires, Ruri caught Senku's eye, and, without a word spoken between them, she led him down a rarely used bridge.

Her companion didn't ask questions, content to follow her for now. After hearing about all the incredible things he had done, Ruri knew that he was wise enough to discern that she had led him away from the others for a reason.

And it was strange that after the years that Ruri had spent memorizing every single word of the Hundred Tales, there was something else, something closer to her heart, that she needed to talk about during the very first time she was alone with Ishigami Senku.

She stopped in the middle of the bridge and looked out at the edge of the water, taking a deep breath and enjoying the fact that she could. Senku, still silent, faced the same direction, placing his hands on the rope barrier as he waited for her to speak.

When she finally did, Ruri told him about herself and Kohaku.

This story wasn't nearly as grand as the one she had told everybody earlier, but Ruri saw that Senku still listened with the same level of close attention. And when she was finished…

"So that's why the lioness didn't trust Gen at first," Senku mused.

"After what I had done, Kohaku made sure she would never be fooled by words again. But it only…"

_It only worked because it was me._

"After that, she still fetched hot spring water for me everyday, but she didn't stay anymore. As soon as she emptied her pot, Kohaku would run. But one day, she was away for the whole day and the whole night. And when she came back, I knew something had happened, because her hair was tied differently from before."

Ruri thought she saw Senku smile out of the corner of her eye, but when he didn't say anything, she continued.

"Little by little, Kohaku started to tell me things…"

* * *

_"Here's your hot water, Ruri-nee. I'm glad I was able to escape Chrome for a while."_

_After thanking her sister for the second batch of hot water, Ruri couldn't help but ask, "Escape Chrome?"_

_Kohaku nodded. "Last night, I really tried my best to hold on, but he made me fall off a tree. I just couldn't take it anymore," she said, shuddering._

_"Anyway," her sister continued, "I should be getting back – he's all alone with Chrome." With that, Kohaku smiled and gave her a wave before running to the bridge that separated the tower and the arena from the rest of Ishigami Village._

_Still confused, Ruri waved back before falling into a somber silence. She had missed Chrome very much during the years… but he must have changed a great deal during their time apart if he was now the type of man who would push Kohaku off a tree and make her feel relieved that she was able to escape._

* * *

_"Did you know that we're moving around the sun, Ruri-nee?"_

_"You should have seen it; he said it was called 'electricity.'"_

_"Look! Isn't it pretty, Ruri-nee? It's like ice that doesn't melt!"_

_"Chrome's been practicing his fighting for you, Ruri-nee_ _."_

* * *

"…and things changed. She would drop off the hot spring water for me, and then, after telling me a little about her day, Kohaku would **_run._** "

Senku chuckled.

"She ran before, and she's running now? Aside from the talking thing, that sounds 10 billion percent the same to me."

And Ruri tried, the best way she could, to explain to the man beside her how different it was, and what it meant to Ruri to see Kohaku change from somebody who **_ran away_** because she couldn't bear to look at her dying sister to somebody who **_ran to_** good people and delicious food and non-melting ice; who **_ran to_** a new friend who showed Kohaku a life beyond the monotonous, backbreaking work of bringing her sister healing water to delay her death by inches.

Her sister's giggles about her new friend's reaction to Chrome's endless questions; the glazed look in her eyes as she tried to describe to Ruri how delicious chewy foxtail grass soup was; her laughter as she told Ruri how she once had to carry that new friend up a mountain like a kitten; the frown that Kohaku determinedly tried to keep on her face as she grumbled about the irritating man who called her a lioness…

…the looks of wonder, and exasperation, and cheerfulness, and worry, and **_hope_** that Ruri saw in Kohaku's eyes during her brief visits; looks that filled Ruri with indescribable joy because her beloved sister was no longer alone in the world…

Ruri was grateful.

_Thank you, Senku._

After a few more minutes of conversation, Ruri knew it was time. Solemnly, she turned and walked across the rest of the bridge and into the forest, knowing by his quiet steps that Senku was following her lead.

As they both made their way through the trees, she spoke.

"The last part of the story is a message from your father. I thought you're the only one who should hear it…"

* * *

_"Ruri-nee, Senku said… that it wasn't useless. All those years… they made a difference."_

_Ruri knew that she was holding in her hands a jar of medicine that would save her life._

_But, in that moment, all she could see was the utterly lovely shade of blue Kohaku's eyes had turned as she told Ruri that Senku said all those years of carrying hot spring water, day after day, had mattered._

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** If there's anybody in the whole world who loves Kohaku enough to analyze her every smile and laugh and facial expression, it's Ruri ^_^ I wanted to share this chapter with you because, during the course of this fanfic, even if Senku doesn't fully realize the effect he has on the people around him, there ARE characters in the story who are making their own observations. Ruri is one example, and Gen, when he shows up, will be another :) And more characters, of course! Unfortunately, because this fanfic is from Senku's perspective, we're going to get his dense version of events most of the time XD The next chapter will be from Senku's perspective :D
> 
> \---
> 
> **II. Important author's notes:**
> 
> Hello, everybody! :) Thank you very much for reading the first chapter of my fanfic! :) In writing this story, my number one goal is to write a Senku/Kohaku fanfic that is one hundred percent in-character, and my second goal is to make this story one hundred percent canon-compliant ^_^ This fanfic will explore Senku and Kohaku's friendships and relationships both with each other and with the other characters (for example, Kohaku and Ruri's sisterly relationship).
> 
> I also wanted to let you know that this fanfic will be a slow burn romance ^_^ If that isn't the kind of story you're looking for, I'll understand if you choose to not continue reading this fanfic, but thank you for reading this first chapter and giving this story a chance! :D
> 
> "If you're already at your limit... I'll go all in with the little gunpowder I have left and try risking it to blow this off of you. But if you can hold out... then it'll take enough time to make you wanna die, but I'll be able to save you 10 billion percent!" Remember when Senku said that to Kohaku the day they met? :D
> 
> To the readers who decide to stay, I'm telling you now, this Senku/Kohaku fanfic will be slow burn... so incredibly slow burn that "it'll take enough time to make you wanna die." To quote the work-in-progress dearest to my heart, "Love grew from moments spent together; from shared interests; from confiding in each other and sharing problems and giving advice; from affection and respect." That's the kind of Senku/Kohaku fanfic this will be: shared moments, confiding in each other, affection, respect. And if you decide that that's the kind of fanfic you want to read, thank you so much for staying! ^_^
> 
> \---
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter One ("Ruri")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
> \---


	2. (S01 E07a) Lioness

**Chapter Two: (S01 E07a) Lioness**

Senku and the girl he met yesterday walked through the forest, with Kohaku slightly in front, carrying a large earthenware pot, and Senku following her. Kohaku seemed familiar with the area, never showing any signs of hesitation.

"That long-haired guy from earlier…" said Kohaku, glancing back at him, "…you're fighting with him, right?"

That, in Senku's opinion, was an understatement. Two days ago, Senku had been dead, killed by Tsukasa's blow to his cervical nerve. If Taiju and Yuzuriha hadn't figured out what Senku's plan had been, that would have been the end of their plan to save all of humanity.

He nodded in response.

"Let's work together then! I can't shamelessly back down from him either."

Why did Kohaku fight Tsukasa in the first place? Tsukasa's focus on youth meant that he wouldn't have gone out of his way to hurt her if they had crossed paths by chance.

Well, whatever the reason for their fight had been, Senku knew that Tsukasa's immediate goal would have been to secure the Cave of Miracles… yet even after their altercation, Tsukasa had chosen to trap her under a fallen tree trunk instead of resorting to other methods to immobilize her.

Tsukasa had chosen not to stay because he had plans for the Cave of Miracles – plans that were in direct opposition to Senku's. And because Senku was fighting for the lives of seven billion people, he couldn't back down from Tsukasa either.

"Right," he said to Kohaku as he followed her. "That's why I'm going to create a country of science."

"Science? You mean that sorcery?"

_Sorcery? Does she mean the pulleys?_

No, that wasn't right – she had seen him make it out of wood, dirt and knotted rope. And soap, which he admitted was a scientific item, but he had only used it to avoid the ropes fraying due to friction.

It was a simple mechanism, the pulley. Still, it had taken Senku several hours to make it, because he had only been one person working on it. It was just like his first six months after waking up – living in this stone world, working alone day after day, he could barely survive. That was why human beings preferred living in communities – for safety in numbers as well as for manpower for shared labor. With a community came more time for individuals to prepare and plan and dream and look beyond survival.

"Anyway," he said, "first things first. We need manpower."

Kohaku nodded.

"Then you should come with me. I was going to head back after getting some hot water."

As they stepped out of the forest, Senku laid eyes on… hot springs?

From her familiarity with the forest and the pot she was carrying, Kohaku probably come here quite often. But why did she need hot water?

"Hot water?"

He watched Kohaku kneel at the edge of the hot spring and dip the pot in the water, waiting for it to fill up. When it was full, she put her right foot in front and pushed herself up, spilling a little water in the process as she stood.

"I make a hot springs bath out of this by bringing it back home. For recovery purposes, that is."

_Recovery purposes?_

Depending on the nearby land deposits, Senku knew that hot springs in Japan could hold a variety of minerals.

_Aluminum, calcium, carbonic acid, hydrogen sulfide, magnesium, potassium, sulfate, zinc…_

Hot springs were formed when water from the earth's first layer, the crust, fell into its second layer, the mantle. Because of the mantle's significantly higher temperature, surface water that made its way there was eventually sent back up as very hot water, or very hot gas – the two main components of a basic hot spring. The heat from both would dissolve minerals in their journey from the earth's mantle to the earth's crust, bringing their curative benefits to the surface.

However, not all hot springs were all the same, because different parts of the world had different minerals. A hot spring in a mountainous region would have different minerals from one in a volcanic region. In fact, even hot springs relatively close to each other could still have different mineral compositions based on the layers of rock underneath, opening a world of possibilities in healing.

But that didn't really explain why Kohaku needed the hot water.

"No matter how I look at you, you're 10 billion percent the very picture of health," Senku said incredulously. "Why would a perky, vivacious lioness possibly need to get any healthier?"

"I'm not a lioness!"

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** Readers who were here during the first two weeks of this fanfic will know that this chapter was this story's original Chapter One ^_^ Ahh, the very first time Senku calls Kohaku a lioness... :D
> 
>  **II. Question of the day:** What do you think of Senku and Kohaku's first meeting? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Two ("Lioness")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	3. (S01 E07b) Blowing Bubbles

**Chapter Three: (S01 E07b) Blowing Bubbles**

"How many people? Let's see…" Kohaku tilted her head down to get a better view of the village in the distance. "That's Shovel running to Shou… Arumi and Natori sitting on a bench… Namari drawing on a piece of leather and Sagan drying fish on the roof…"

Senku shot her a strange look.

_Seriously?! She can see all of that from this far- wait…_

Those names sounded familiar.

_Shovel, a tool for digging… Shou, sunken rock… Arumi, aluminum… Natori, sodium… Namari, lead… Sagan, sandstone…_

As they walked down the mountain, Kohaku continued.

"…Berry and Shirogane are holding those baskets filled with mushrooms, Azura and Sango are washing clothes, that's Carbo preparing that boar, Unmo's helping Kaseki fix the straw on that roof…"

 _There's no mistaking it,_ thought Senku. _Berry, beryllium… Shirogane, white gold… Azura, azurite… Sango, coral… Carbo, carbon… Unmo, mica… Kaseki, fossil… somebody must have taught them all these words. But who?_

After reaching the rope bridge, Kohaku steadied the pot in her arms so that she could maintain her balance as she walked.

"…I don't know exactly how many children and elderly we have, but aside from them, there's… about forty of us!"

_Forty people in a settlement like this? Where did they come from? Was there a scientist before me who broke out of the petrification? But to get to all this… several people would have had to be depetrified at the same time. Maybe a group of mathematicians who counted like I did? Or possibly just one scientist like me, who broke free and discovered the formula for the revival fluid?_

Suddenly, two shadows leaped toward him, weapons drawn…

_What's happening-_

…only for Kohaku to overwhelm both of them in an impressive display of acrobatics that gave her the reach to block their attacks before quickly dropping to the ground right in front of Senku.

Defeated for now, the two shadows – who turned out to be two guys around Senku's age – fell back warily.

"Stop attacking us, Kinro, Ginro!" she scolded. "My life was saved by this man!"

As they told her that somebody saving her life was no reason for them to let that certain somebody enter their village, Senku moved to the side to get a better look at the two men, who seemed to be the village's guards. The blonde one kept sneaking perplexed looks at Senku, as if he had never seen an outsider before, while the stern, black-haired one unapologetically reminded Kohaku that rules were rules.

"Oh? If that's really what you're saying, then what has to happen has to happen," said Kohaku casually, her tightened grip on her left dagger starkly contrasting her light tone. "Looks like I'm just going to have to fight both of you. You two will go easy on me, right? You're sure to win! This is two against one, after all…"

While Senku knew that eyes couldn't possibly change color after a child entered adolescence, from what he just saw, he could almost believe that during her taunting, the normal color of Kohaku's eyes had turned into the unyielding blue shade of chalcanthite.

Then an idea occurred to him.

Chuckling, Senku walked up to Kohaku's pot and dipped his fingers in the water.

"This whole situation looks ready to blow. And that's one scaaaaary face you're making to top it off."

After fishing his trusty bar of primitive soap out of one of his bags, Senku scooped up some water and rubbed the soap into it. The introduction of the soap decreased the water's surface tension, making the water in Senku's hand thicken into the milky color of soap lather.

Forming a circle with his thumb and forefinger, he breathed out a long puff of air and watched as the combination of water, soap and air left his fingers and instantly formed into several spheres – the natural form that bubbles normally took due to that particular shape having the smallest surface area to volume ratio.

"Rah!" yelled the taller guard, attacking a bubble, only to see it split off into more, though exponentially smaller, bubbles.

"Wow, these jewels… are just floating… so pretty… how…?" wondered the other one, trying to jump up to reach them.

While the two guards were mystified with the bubbles' color-changing properties, which were nothing more than light reflecting between each bubble's inner hydrophilic layer and outer hydrophobic layer, Senku was gaining valuable information.

"Ahhhhh, now I see their level…" Senku grinned, continuing to watch their increasing confusion at something so simple that even children from his era had no problem enjoying.

_If they don't even know what bubbles are… this will be a piece of cake._

"Alright, I accept! Forty people, I'll take all forty of them…"

Senku could see it in his mind's eye - the whole village cheering at the new innovations brought to their lives, and himself, controlling a giant robot and waving his flag of science as he led them into the future.

"I'll get forty of these people using science they've never seen before… all those allies, all that manpower…" He laughed lowly as he spread his fingers, easily imagining all of them in the palm of his hand. "Now this is getting me excited…!"

He heard Kohaku cough.

"Speaking of scary faces… I think yours tops them all," she said flatly.

Then she paused, thinking.

"But if that's your plan, then to start off… you should get Chrome!"

"Who's that?"

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** Kohaku defending Senku... :) I had to learn about how bubbles were made to write this chapter XD Before this, I had no idea that bubbles had multiple layers! O.o
> 
>  **II. Question of the day:** How do you feel about Senku's scientific way of looking at bubbles? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Three ("Blowing Bubbles")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	4. (S01 E07c) Sulfur Ball

**Chapter Four: (S01 E07c) Sulfur Ball**

As it turned out, Chrome was a self-proclaimed sorcerer who believed that salt, copper sulfate, and sulfur flame colors and a sulfur ball's static electricity were due to sorcery.

"Were these all your ideas, Chrome? You have all kinds of scientific minerals in that shed of yours…" Senku glanced up at the storehouse, "did you go around all by yourself, gathering everything you have in there?"

"Exactly! But what's it to you?" Chrome replied defensively.

He then told Senku about what he had done throughout his childhood, which he had spent collecting everything – experimenting with mixing and burning and melting.

Senku smiled in satisfaction.

The flame tests were something kids learned in elementary school, and it was easy enough to throw random particles into fires to see what would happen. Melting greater amounts of minerals was more interesting, but also more risky, due to certain chemical gasses having detrimental or even deadly effects.

In the course of his collecting, Chrome had probably obtained a significant amount of sulfur. It was one of the most common minerals in the world, making up for almost three percent of the planet's composition. If somebody were to take all the sulfur on the planet and put them together, there would be enough to form two new moons.

Because sulfur was easy to find, it was easy to replace, and therefore convenient to experiment with. Not satisfied with just creating colored fire, Chrome had taken several pieces of it, melted it at 115.21 degrees Celsius, waited for it to cool down, and broke the earthenware pot to see his new creation.

If he had rubbed his hands on his clothes before touching the ball, the friction would have resulted in static electricity. And from there, Senku could see his way of thinking – if rubbing the sulfur ball a little with his hand could create a bit of energy, then rubbing it a lot would create even more energy.

_Even if he didn't know what he was doing was experimenting, that was exactly what he was doing. And even if Tsukasa kills me, there will always me crazy idiots like this Chrome, who'll try everything they can think of with everything they can get their hands on… because nobody can stop science!_

With that in mind, Senku stepped up to Chrome and explained the situation – since he, Senku, was starting a kingdom of science to fight against a certain somebody else who was ridiculously overpowered in the stone world, then Chrome, who would certainly be one of Tsukasa's targets, would surely be completely fine with handing over all the scientific materials he had collected over a long period of time to somebody he had just met.

 _He had salt… although that's one of the easiest things to get… but what else does he have up there? Chrome could have anything!_ thought Senku gleefully, climbing up the ladder to get inside Chrome's mysterious scientific treasure trove. _Copper and sulfur… sulfur is usually found near hot springs or volcanoes… and if he found sulfur, he might also have barite… gypsum… pyrite…_

"Of course I'm not just going to give you all my stuff!" he heard Chrome screech. "Get back down here!"

Already halfway up the ladder, Senku looked down at a seething Chrome, then up at the door that was blocking Senku's view of all those secret scientific materials. He glanced at both back and forth.

_Chrome. Scientific materials. Chrome. Scientific materials._

_…Scientific materials, obviously!_

He started moving upwards again. In Senku's opinion, there wasn't really any point in being _out here_ when all those scientific materials were _in there._

"What- hey! Oh… fine then! If you won't listen, then just face me one-on one! Let's have a duel!"

Senku paused, listening.

"If I win, you ask for my forgiveness on your knees and leave this village forever… and if you win, I'll give you every single thing inside my sorcery shed!"

After pondering Chrome's challenge for a moment, Senku jumped down to the ground.

"You want to duel?"

"Yeah! I'm going to show you crazy techniques you've never seen before! Just you wait! I'll totally defeat you!" Chrome stepped forward in determination and pointed a finger at him. "So get ready… for our arithmetic duel!"

_Arithmetic? I wasn't expecting that._

Meanwhile, an exasperated Kohaku shook her head. "Why do I get the feeling you won't even be a match for Senku?" she muttered, before moving to stand behind him.

On the other side were Chrome, who looked all fired up, and Kinro and Ginro, who both seemed mildly interested.

Between them and to the side stood the scientific storage shed.

"Get ready for my super technique… my incredible arithmetic…" said Chrome, putting his hands in a frenzied grasping position over his head, as if between his fingers were a fireball that he was going to launch at Senku and Kohaku.

He continued, "Here I go… what do you get… when you have eight sets of eight?!"

And Chrome fired his imaginary fireball… although from the duration his hands spent in firing position, he seemed to be imagining firing some sort of powerful laser beam instead.

_Not that he knows what a laser beam is, but anyway… Eight sets of eight? Easy._

"Sixty-four," he replied easily – although what Senku hadn't expected was Kohaku, who was now next to him, speaking the same number at exactly the same time.

_Do they study arithmetic here?_

Apparently not, judging by Chrome's absolutely gobsmacked expression.

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** The arithmetic battle is quite amusing in the manga - especially the last part! XD
> 
>  **II. Question of the day:** What do you think of Senku's priorities? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Four ("Sulfur Ball")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	5. Chrome

**Chapter Five: Chrome**

Chrome tried his best to fall asleep, but every time he closed his eyes, they would instantly open back up, unwilling to rest after the incredible things he had heard from Senku, trying to see the past that had been swallowed up by the petrification.

_My human ancestors… made metal houses that could fly… and they even walked on the moon? And… arms from metal? They used their science to heal? Senku said he knew about a cure-all…_

Deciding to leave his collection shed to get some air, Chrome tiptoed past a sleeping Senku to open the door and tried to descend using the ladder as slowly as possible so that his new friend wouldn't be disturbed.

A voice made him realize he wasn't alone.

"Chrome? You're still awake?"

It looked like his absentminded walking had led him to Kohaku's favorite tree.

Hearing Kohaku's voice made Chrome wonder how she had crossed paths with Senku. While he had only known Senku for several hours, Chrome had known Kohaku for many years, and Senku was the first person she had ever brought to the village.

"I couldn't sleep."

"Yeah… me neither."

In fact, until meeting Senku, Chrome had no idea that there were people outside their village who weren't previously exiled criminals. And if, for example, there actually were other villages somewhere out there besides Ishigami, a man wandering in isolation could possibly have been an exiled criminal of one of those communities.

_Well, I won't know until I ask._

"How did you meet Senku?"

Not only that, but out of everybody in Ishigami Village, Kohaku was the most protective of Ruri. Bringing an outsider to the village border would have been a risk, especially one with the scientific knowledge Senku had at his disposal. What had made her take the gamble?

"He created something impossible and saved my life."

_Something impossible?_

Chrome waited for Kohaku to elaborate, but when she didn't, he was left to his thoughts.

Having met her when they were both young, Ruri was one of Chrome's very first friends – but when her illness eventually required her isolation in the Priestess' Tower for her own safety, he began to spend more time with Kohaku, who was the only other person who…

_…who still had hope._

Rain or shine, storm or snow, Kohaku fetched hot spring water for Ruri, and Chrome searched for cures for Ruri. If Senku had made a promise to Kohaku about healing her sister – or, if he had even hinted at the possibility, it would have been the very first thing Kohaku would have told Chrome, and definitely before the sorcery battle began.

_Which means… she doesn't know yet._

"Kohaku… about Ruri… Senku said he knows about some kind of medicine, a cure-all… but we don't have everything we need to make it."

She didn't respond.

"If we get everything, though," he continued, "maybe… there might be a chance…"

_…that Senku can create something impossible and save Ruri's life._

Silence.

Chrome looked up at the stars.

_There's some kind of medicine out there._ _One that our human ancestors made. A cure-all… something that can cure everything._ _It must be amazing…_

And, after a long time, he heard Kohaku speak.

"I've wanted Ruri-nee to be better… ever since I was old enough to want anything."

"I know."

* * *

After that, they didn't speak for a while, choosing to spend their time together in silence. But Chrome knew that Kohaku felt exactly the same way he did – eager for the next day to begin.

_Tomorrow, I'll ask Senku if we can start making it. And then-_

Quick as lightning, Kohaku was suddenly right in front of him.

"Whoa!" Chrome yelled as he jumped back in surprise. "Kohaku! Don't scare me like that!"

"Tell me," she said urgently, stepping closer to him. "Tell me _everything_ you talked about after I left to bring the hot springs water to Ruri-nee."

"Everything?"

She nodded determinedly before jumping – _it is so not fair how she can jump that high!_ – back up onto her usual tree branch.

"Yes. I want to know everything."

 _Actually,_ thought Chrome, _I can see why she wants to know. Senku did tell me a lot of interesting things._

"Alright, then. Let's see… after you left, Senku and I stayed in my collection shed and talked about…"

Chrome went over everything in detail, talking from the late hours of the night until the first rays of sunlight shone over the mountain.

"…and about galena, we talked about it again too and he said that it's normally super shiny when you dig it up but something about the air makes it less shiny after it's been out a while so you have to break it into pieces to see it be shiny again which was funny because I've smashed it to pieces before not this one but other ones and the inside parts were super shiny so he was right and he told me breathing in galena dust can make you really sick so you have to be careful digging it up but touching big pieces is pretty much fine and in his era people usually found galena with other rocks called chalcopyrite and pyrite and sphalerite and tennantite-tetrahedrite…"

Suddenly, he heard a thud.

"Kohaku! What happened? Are you alright?!"

His friend, who had just fallen off her tree, was sprawled out on the ground, dazed, with her eyes almost looking like… spirals?

Chrome coughed.

_Maybe I… shouldn't have talked about rocks so much…_

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** I hope you liked this chapter - as you know, it's the second non-Senku chapter! :D Because Chrome and Kohaku have both been working for years to try and cure Ruri, I feel like they would have a special bond, and that Chrome knows Kohaku's heart in a way that very few people do :)
> 
>  **II. Question of the day:** How do you feel about Chrome's thoughts about Kohaku and Ruri? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Five ("Chrome")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	6. (S01 E08a) True North

**Chapter Six: (S01 E08a) True North**

Using his stick, Senku pointed at the comprehensive scientific roadmap he had sketched in the dirt.

"We're going to have to force our way through generations and generations of scientific history," he explained to Chrome and Kohaku. "No taking the scenic route for us – we're basically traveling through time."

Chrome tracked the roadmap backwards with his finger in the air. "If everything starts with that "iron" thing, then we should make it first, right?"

"That's right. Without iron, we won't be able to make the tools and everything else we need."

"If it's that useful, then it must be super important!" Grinning maniacally, Chrome continued, "You have to tell me all about it! Teach me everything!"

"It won't be that easy to explain iron… we'd have to go into geology, climatology, chemical structures of elements, physics theories…"

Already, Kohaku seemed to sway slightly where she was standing.

"This will be Senku-sensei's sorcery… science class? Even if I listen, I don't think I'll understand. And…" she continued, giving Chrome a sideways look, "…I don't think you know what you're getting into, Senku."

Eyes narrowing in slight suspicion, Senku also looked at Chrome.

_What does Kohaku mean by that…?_

* * *

"No, it's not a rock. Iron is a type of metal-"

"It is? Is it in my shed? I've collected everything around here that looked interesting, but if you haven't seen it in my collection, that means we have to go find it, right? Where should we go look? Can we find in a mountain? There are a lot of mountains here and I've explored all of them; do you want to join me? You probably should because you know how it looks like, right? Should we bring big axes, or will smaller ones be fine? And why do we need to have it anyway? What does it have to do with the cure-all?"

"We're going to use it to make magnets-"

"You can make magnets? But you said that the rocks we're going to use are magnets, right? So why do we need more magnets? Or do you need to make a magnet that's bigger than the ones we have for some reason? Are magnets useful for anything besides seeing which way is north? How do magnets even do that, anyway? How come the magnets I found can tell me where north is, but my other rocks can't? A magnet is just a rock, right? How can a rock find north? What makes magnets always point north? Are some magnets more accurate than others? Have you ever made a magnet before? Are they easy to make? How are we going to make them? And are we going to just make one, or more than one? When we make the magnet, how do we teach it how to point north? And how will we…"

* * *

Twelve straight hours of Chrome's questions later, Senku lay weakly on the ground.

_Now I… totally know…what Kohaku meant by that…_

As Chrome expressed his amazement at the Earth's daily rotation and yearly revolution, Kohaku, who unfairly did not look as worn out as Senku despite the fact that she had ducked out of the endless questioning for a while in favor of a couple of hot springs water runs for Ruri, had a question of her own.

"That's so weird. Then why am I not thrown off this branch right now?"

Clearly, Kohaku was no ally of Senku's. Why else would she ask questions of a clearly exhausted man? Nevertheless, more science had to be explained.

"Because of something called gravity…"

And that was all Senku could manage before he had to wheeze for air.

_So… much… explaining…_

After that, Chrome made an observation about the North Star – although he hadn't known what it was called. After staggering to his feet, Senku told him its name and cautioned him to remember the star's purpose... and then he noticed Kohaku peering at the sky.

"True north seems slightly off, if you ask me…"

"That's not possible. The margin of error is…"

He froze.

_It moved. We moved. Even though the Earth's axis only moves by a fraction of a fraction of a percent each year, those fractions of fractions add up over three thousand seven hundred years. The Earth's axis has tilted, and because of that, what was north in my time isn't north anymore…_

Senku laughed self-deprecatingly, putting a hand over his face in embarrassment.

"Some scientist I am, letting my preconceived notions get in the way of what's in front of me, instead of being observant like these two. What a useless guy I am…"

_But now, the best thing to do is to learn from this and apply it to the future. At the very least, now I can make a sextant that actually works, now that I know what went wrong with the last one._

"Ha! Looking at you, Senku, I don't see somebody useless," Kohaku said warmly.

_This was a learning experience. Discovering how to work with new information is exactly what a scientist is supposed to do._

"Yeah, I'm not trying to beat myself up over it," he replied. "After calming down, I can see that it's the scale of things…"

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** At first, I had the idea of writing that Senku brushed off Kohaku's warning (and say something like, "I can talk about science all day!"), but I decided to write it the way I did instead. After all, it doesn't make sense for Senku to not listen to Kohaku since he's trusted her so far, right? So instead, Senku got suspicious as well... and, as it turns out, his suspicion was justified XD
> 
>  **II. Question of the day:** What do you think of Senku and Chrome's talking stamina? XD
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Six ("True North")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	7. (S01 E08b) Waterfall Plunge

**Chapter Seven: (S01 E08b) Waterfall Plunge**

After taking off their footwear and dressing down to clothing more suitable for spending long amounts of time in the water, Senku, Chrome, and Kohaku waded into a river, pouches at their waists and magnets clutched in their hands.

"Iron sand is mostly composed of magnetite," Senku told them as he stooped low with his magnet, "which should be attracted to the magnets Chrome gave us. It's heavier than normal sand, so there should be some at the bottom of this river."

Kohaku also bent down to try, pushing the magnet in her hand into the riverbed for a few moments before holding it back up above the water. Grains of dark grey iron sand were stuck to Kohaku's magnetic rock in rough spikes.

"Whoa, so much is stuck to it! This strange black sand is…?!"

"Yeah," Senku said, idly noting that the mass in Kohaku's hand looked like a small, dark, baby hedgehog, "that's exactly what we're here to get. Iron sand acquired!"

And, for hours after that, the three of them gathered iron sand in the river…

…before a thought occurred to Senku.

* * *

Ten minutes later, throwing caution to the wind, Senku jumped over the edge of the waterfall at the end of the river, holding his clothes above his head as a makeshift parachute to slow down his descent.

_With this much momentum, the effect of wind resistance won't help that much, but it's still something._

Behind him, Chrome, who was being swept down by the current, was hugging a log for dear life.

"But I don't wanna go down a waterfalllll…"

Despite Chrome's preferences, the current didn't seem to want to stop to let him get off his log, so all he could do was hang on, and after two huge splashes, they both made it safely to the bottom…

…only to find that Kohaku was already there – and her magnet was already covered with a new batch of iron sand.

"Kohaku? How did you get down here so fast? And why aren't you wet?" grumbled Chrome as he got off his trusty log.

She blinked.

"I jumped from one rock to another to get down here. Why would I get wet?"

* * *

"Looks like there's way more iron sand down here!" exclaimed Kohaku, whose magnet was getting put to good use. She quickly deposited the sand into her pouch before once more using her rock to attract more. "They just keep coming and coming!"

Chrome, who was collecting sand in shallower water, asked, "You said it was because of the water pressure, Senku?"

He nodded.

"It's because of the difference in speed between rushing water and stagnant water. The pressure from the waterfall pushes the iron sand from up there to down here, and after it gets here, the comparative lack of pressure from the continuing river makes the iron sand lose the momentum it gained while it was in motion, so it stays at the bottom."

"Looks like there's more sand near these rocks," Kohaku observed, emptying her magnet again. "And I didn't even get all of them…"

As she bent her knees to get closer to the water, Senku yawned and absently scraped the iron sand his own magnet had gathered into his pouch for safekeeping. They had been gathering sand at the river for a few hours before the thought of jumping down the waterfall had crossed his mind, and the warm sun was making him want to take a nap.

Deciding that a bit of a break was in order, he took his bamboo canteen and filled it with water from the gushing waterfall before heading to the shore – only to find that Chrome had had the same idea, holding his own bamboo container in one hand as he gripped the side of a rock with the other in order to climb on top of it.

After wading over to Chrome and settling down on a rock next to his, a cool drink of water helped Senku wake up, but he still wanted a bit of a rest. Chrome, who felt the same way, lay down on his side and propped up his head with one hand as they both watched Kohaku gather black sand.

Despite her feet being wet from being in the river, she was still able to maintain her balance as she jumped down rocks to meet them at the bottom of the waterfall…

…but even then, Kohaku didn't seem fatigued, and Senku assumed it was because she was used to the much more gruelling task of fetching hot springs water. He and Chrome observed her bending down with her magnet, getting black sand, placing what she had gathered in her pouch, with the whole process taking only a handful of seconds.

After doing all of that a few times in one place, she moved a couple of steps to do it all over again, going through the tried-and-true motions of stooping, collecting, and depositing until she had exhausted the place were she stood of iron sand. And once she had, Kohaku again moved away to a different part of the water she hadn't searched in yet and repeated the same pattern, gathering materials with meticulous rigor and increasing success in various areas of the water.

_She's collecting a lot. Just watching her get all that iron sand is making me feel tired…_

"This lioness is amazing," commented Senku as he sipped more water from his bamboo canteen. "Are all the people in your village like that?"

Chrome shook his head. "Nope. Kohaku's the only one who's like that."

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** There's a panel in the manga where Chrome looks adorable while he's panicking and hugging a log while going down the waterfall, so I had to include it here! XD And, of course, Senku's "This lioness is amazing" comment is straight from the manga, too. I wish they had included that line in the anime!
> 
>  **II. Question of the day:** How do you feel about Kohaku's diligence? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Seven ("Waterfall Plunge")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	8. (S01 E08c) Sunflower Field

**Chapter Eight: (S01 E08c) Sunflower Field**

After Kohaku explained Chrome's feelings for Ruri to Senku, he saw why the man had spent years gathering a massive amount of minerals and plants. While Senku, who would have collected the materials for science's sake, couldn't personally empathize with Chrome's personal motivation, he was still benefiting from the collector's years of hard work. A scientist had to be self-aware, and Senku knew perfectly well that if he had been required to gather everything in that shed by himself, it would have taken- well, maybe not 10 billion years, but close enough.

_Everything there takes us closer to healing this Ruri person and getting the village to join the kingdom of science. But if she knows about wild animals from Momotaro, what else does she know? What other stories has she told everybody?_

After he voiced his questions, Kohaku stumbled for a moment – but as an experienced fighter, she was able to find her balance quickly – and chatted conversationally about her sister's tales as she and Senku walked to where the rest of their things were.

It was a good thing that Kohaku was doing all the talking, because Senku really needed all his energy for the steep path they took.

 _The waterfall didn't look_ this _high from up there!_

"Ruri-nee knows lots of stories and long words… she tells us what kinds of fish are good to eat, because there are poisonous kinds as well… and when Chrome started collecting his rocks, she was able to tell him what some of them were…"

When they reached the big rocks where they had left the rest of their clothes, Kohaku continued as they both got dressed.

"…and when babies are born, the fathers and mothers normally go to her to ask what names they should give their kids. I think it was like that with our mother as well…"

"Is that why most of the villagers are named after minerals?"

Kohaku was startled. "Are we?" she asked, picking up her weapons and strapping her shield to her back.

For a moment, Senku was surprised she didn't know, but when he thought about it, it made sense.

_Compared to animals and food, stories about minerals probably aren't the most popular. And even if Kohaku is named after amber, that doesn't mean she's ever seen any. Ninety percent of the world's amber comes from Russia._

_That means that the people she told me about… Arumi, Sagan, Kaseki… they've likely never seen aluminum, sandstone, or fossils, either. But this Ruri, and whoever came before her, suggested those kinds of names. Were they told by the original creator of these stories to do that?_

_If they were, that means that whoever that first storyteller was, he or she knew the value of-_

"Hey, Senku?"

"Yeah?"

"I was wondering…" said Kohaku slowly, looking to her side at the river they were trailing, "how much iron sand are we going to collect?"

Senku weighed it over in his mind, calculating the density of the iron sand, the volume it would be as molten iron, and the minimum weight of the bar of iron he needed for the magnet.

After arriving at the answer, he replied easily, "Just about enough to fill half of the big pot you use to carry hot spring water."

"We need _THAT_ much?!"

* * *

The next day, while inspecting the color of the river moss closely, Senku nodded to himself.

_This is definitely chatsubomi moss. Which means if I'm right, the chemical we need the most to get things started is nearby. But we don't even have iron yet, let alone glass, so I won't have to go there for a while._

Getting up from his kneeling position, he gave the moss a final look before starting to make his way back to the kingdom of science. With Chrome, Kohaku, and Suika helping to gather iron sand, Senku had decided to take the day to scout the surrounding area for a place high enough to place lightning rods for the magnet he was planning to make, and the discovery of chatsubomi moss meant the day was more productive than he had anticipated.

Taking his time, he walked down the mountain, past Kohaku's hot springs, and eventually reached level ground. As he passed fields of wild grasses and flowers, he began to think about the next steps in the cure-all roadmap.

_Once we get enough iron sand, we'll have to melt it to make iron. But wood can only go up to seven hundred degrees Celsius. The only chance we'll be able to more than double that is if we increase the amount of oxygen in the furnace, which means I should make some-_

"Senku?"

Hearing a familiar voice to his left, Senku turned and saw Suika, who had a bulging pouch attached to her rope belt, peering up at him curiously.

"Did you come to watch the sunflowers too, Senku?"

He blinked and looked around. As it turned out, he was in a field of sunflowers. And from what Suika had just said, it seemed like people in the stone world were so devoid of entertainment that they watched plants for fun.

"Watch the sunflowers?" he clarified.

Nodding, she replied, "Suika likes to watch them sometimes! They face that way in the morning," she said, pointing in one direction, "and that way in the afternoon!" she continued, gesturing to the opposite one.

Senku started to explain why sunflowers did so, but was interrupted by a loud growl from Suika's stomach.

"Oops," Suika giggled, turning slightly red in embarrassment, which should have been impossible to see with a watermelon mask on. "I guess Suika is hungry."

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** Kohaku has now found out that they need a looot of iron sand XD Also, Senku's first one-on-one conversation with Suika! :D
> 
>  **II. Question of the day:** What do you think of Senku and Kohaku's conversation? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Eight ("Sunflower Field")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	9. (S01 E08d) Iron Sand (Days 01-14)

**Chapter Nine: (S01 E08d) Iron Sand (Days 01-14)**

The first week they collected iron sand, Senku and the others didn't get very much.

After seeing the pouches Kohaku had filled that first day, and the one that Suika had with her, Senku chose an earthenware pot from Chrome's things that was the right size for the amount they needed to collect.

The good news was that, as he had said to Kohaku, it was only half the size of her hot spring water pot, volume-wise. But the bad news was that when they poured in the iron sand they had managed to gather in those first two days, the meager amount couldn't even cover the bottom of the pot.

Suika stood on the tips of her toes to be able to peek into the pot.

"We… didn't get very much, did we?"

"Don't worry!" Chrome said encouragingly. "I've been collecting materials for a long time – I know we'll get there!"

Nodding, Kohaku said, "I agree! We just need to work hard… and I mean _all_ of us," she finished, directing a pointed look at Chrome.

"Hey! I worked hard these past couple of days!" he protested. "It's not my fault I'm not a gorilla like-"

All of a sudden, Kohaku's head looked like it had inflated to the size of a hot air balloon as she berated Chrome.

Senku shook his head to clear it and rubbed his eyes. He was sure that he was just seeing things.

For the rest of the week, they returned to the waterfall everyday. Usually, it would be Senku, Chrome, and Suika starting early in the morning, with Kohaku joining them a few hours before lunch after she finished bringing Ruri a couple of pots of hot spring water.

All four had magnets, to dip past the rushing water and down to the riverbed, and pouches to place iron sand in. Each dip of a magnet was different – there were times when the whole magnet would be covered, and times when only half, or even less than half, of it was able to attract the sand they needed. And it all went inside their pouches.

They didn't always stay together. Sometimes, Chrome would check on his traps to see if they had caught anything for dinner that night, and Suika would take walks with Chalk to look at flowers or forage for berries. Kohaku would train to keep her fighting skills in shape, and Senku would cut leather to make new pouches for everybody or inspect nearby areas for mineral deposits.

But they worked hard everyday and placed all their iron sand in the iron sand pot before they split off to set up the campfire for the night. And, by the end of the week, they were able to completely cover the bottom of the pot with iron sand.

* * *

The second week they collected iron sand, Senku started to design a furnace.

While ironmaking required iron sand – or at least their version of it did – the venture also required a furnace, which Chrome unfortunately did not have. When asked, the man had answered that earthenware pots and open fires had been sufficient for his past experiments.

But while a furnace hadn't been needed back then, it certainly was now.

 _A cube-like shape would help us heat materials more evenly,_ thought Senku. _That was why ovens back then were cubes or rectangular cuboids. But right now, heat, as much of it as we can get, is our top priority, which means this shape will be more effective…_

After Senku scratched a few lines in some dirt with a stick, Chrome, who had been watching curiously nearby, came closer to look at what he had drawn.

"What's that, Senku?"

"We need a place to heat the iron sand once we have as much of it as we need," replied Senku. Pointing to the remains of their campfire from last night, he continued, "Heating the iron in open air, like when you made your sulfur ball, would leak too much of the heat into the air."

He pointed to his drawing.

"But if we make this bottle-shaped furnace, we can heat the iron inside of it until it melts. After that, we'll pour it into molds and make ourselves iron bars."

_After we get the iron bars, I'll put up lightning rods. Good thing I've already started scouting for places to put them. But the amount of iron we'll have… no point in having ten or twenty lightning rods if we only have one or two bars of iron- wait. If those rods attract lightning, there's a chance that the lightning will shift to the rods that have the iron attached. So setting up a ton of them would be for the best after all._

Senku would have to look for the right material make them. While random wooden sticks were easy to find, they wouldn't be able to support the iron bars.

_They'd have to be thick enough to be stable… maybe bamboo? Actually, I should start cutting bamboo so that I can make bellows for the furnace. But I'll need more leather for those, so I guess I can't start right away anyway. We've been saving the animal skins from our meals, and after drying them, we'll get enough leather eventually – and it'll take time to get all the iron sand we need, anyway. We can get everything we need – it'll just take a lot of time._

"Iron bars…" Chrome repeated, looking first at the drawing, then at their pot of iron sand. "We're going to need way more sand, aren't we?"

Senku nodded. "A lot of it."

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** While the collection of iron sand was mostly skipped in the manga and anime, I think that gathering THAT much sand would have taken weeks and weeks. Over the next few chapters, if you get so sick of reading about iron sand that you just CAN'T TAKE IT ANYMORE, please remember that if there's one thing MORE boring than reading about weeks and weeks of collecting iron sand, it's WRITING about weeks and weeks of collecting iron sand, hahaha! XD I wish I could just skip the iron sand chapters and go straight to "good stuff," like Senku and the others making ramen, Gen's first appearance, etc., but because Senku likes the tiny details of scientific processes, I felt that it would be in-character for him to notice the long process of gathering scientific materials, step by step :)
> 
>  **II. Question of the day:** How do you feel about the start of their iron sand journey? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Nine ("Iron Sand, Days 01-14")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	10. (S01 E08e) Iron Sand (Days 15-28)

**Chapter Ten: (S01 E08e) Iron Sand (Days 15-28)**

The third week they collected iron sand, Senku and the others continued to work day in, day out.

If Senku had been in his era, he would have build a robot to do all this bending for him. Then again, if he had been in his era, he could have just walked into a pharmacy and purchased antibiotics.

But in the absence of scientific advancement, muscle and hard work reigned in the stone world. And while Senku didn't have the former, he was more than capable of the latter – and, as he was coming to find out, so were the others.

Bend.

Magnet.

How much?

Enough?

Pouch.

Again.

There were benefits from keeping at it for so long – their soreness was being reduced as their bodies started to get used to the endless motions of bending and stooping, and they were identifying little dips and pockets in the river where iron sand was more likely to accumulate, and where it would be easier to collect.

And, at other times, they would move further along the river, to look for more places to continue their gathering, to search for new dips and pockets in the riverbed.

But every single day, their goal was always the same – to get as much iron sand as they could from the river into their pouches, and from their pouches into the iron sand pot where they kept all of it.

Their hard work was paying off, too – after completely covering the bottom of the pot at the end of the first week, Senku, Chrome, Kohaku, and Suika were seeing the little increments their contributions were making to the pot. The increments were a little too… well, little, but with the four of them, doing steady work wasn't as difficult as it used to be for Senku.

A little more one day, and then a little more the next day. Little by little. Always just a little, but it was better than nothing, and science was always like this, one step leading to the next.

 _It would be much easier,_ thought Senku, _if we could find an iron deposit. But the time we'd spend looking for one… all wasted if we didn't find anything._

Which was precisely why, when he got new ideas where to look, Senku went by himself. There was no point in going with the others and stopping, even temporarily, the collection of iron sand.

And it was on one of these excursions that he saw Kohaku doing some odd motions in the shallow part of the sea.

But Senku's purpose was to look for minerals, not to speak to her, so he gave a shrug and moved on.

Other tasks aside, they all returned to the river eventually, because there was always more iron sand to be gathered.

* * *

The fourth week they collected iron sand, Senku, Chrome, Kohaku, and Suika visited the beach.

After having spent many, many days looking for sand in the river, Senku noticed that his supply of calcium carbonate – which he needed to make soap – was running low. Which meant going to seaside to collect seashells.

"Seashells?" Kohaku asked. "What for?"

Senku chuckled and took a small lump from one of his bags.

"One of the things you can make with seashells… is soap!" he declared, holding the small piece he had in his hand for everybody to see.

He was down to his last bar of soap, which he had made while he, Taiju, and Tsukasa had still been tentative allies.

After standing on her tiptoes to look at the object, Suika said, "It's very small! What is it?"

Before Senku could answer, Kohaku exclaimed, "It's the same color as the rock you used for your sorcery!"

"Sorcery?" asked Chrome, his interest piqued.

When Kohaku explained how Senku had made orbs appear by using the rock and some water, instead of being unimpressed, Chrome was even more curious.

"You can make those without charcoal? How?"

Senku opened his mouth to explain- only to see Kohaku give a small grin as she looked away, which made him pause.

_Wait… the last time I did this…_

The memories of answering Chrome's questions for twelve straight hours came flooding back to Senku, and he almost shuddered.

"Actually… I'll just show you…"

And that was how the four of them ended up at the beach that day to gather seashells.

With four people on seashell duty instead of just Taiju, they were able to fill the baskets they had brought with them before the day was through. After a couple of hours of Chrome and Kohaku fishing for dinner while Senku and Suika gathered firewood, the four of them decided to make camp in a nearby clearing for the night and set down baskets of seashells, reminding Senku of another time when he had camped in a clearing for the night with a sack of crushed seashells and eaten delicious food with people he should have been able to trust.

_Heh. I wonder how the Tsukasa Empire's doing?_

Three allies, salted grilled fish, a roaring fire. Three allies who had been helping him collect iron sand for four weeks, to make something they had never seen, to create something else that existed nowhere in the stone world except in their imaginations and in Senku's memories of modern medicine.

Even so, Senku didn't tell them that seashells could be used to make four things.

He knew better than to make the same mistake twice.

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** Even though Senku doesn't trust them completely yet (he's only known them around one month at this point, after all), he does like Kohaku, Chrome, and Suika :D He's just cautious enough and realistic enough to not be as open with them as he would be with, for example, Taiju, whom Senku DOES trust completely :D
> 
>  **II. Question of the day:** What do you think of Senku's caution in keeping information from Kohaku and the others? :O
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Ten ("Iron Sand, Days 15-28")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
>  **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	11. (S01 E08f) Sunflower Treat

**Chapter Eleven: (S01 E08f) Sunflower Treat**

At the end of the fourth week of collecting iron sand, Senku, Chrome, Kohaku, and Suika were at the same river, bending and gathering as much sand as they could. Meanwhile, Suika's dog played on the riverbank, letting out little yips and barks to try and catch his playmate's attention.

After spending the whole morning filling two pouches with iron sand, Senku dropped his magnet in yet another pouch and began to wade out of the river.

"Looking for minerals again?" asked Chrome.

Senku shook his head. "No."

Beside Chrome, Kohaku straightened up and peered at the sky.

"The sun's bright today, so the animals might be out… I might be able hunt something for dinner in the forest. Chrome, Suika, do you want to come?"

They both indicated their refusal.

"Suika will stay here for now," said the little girl, "and use this magnet some more!"

"Good luck, Kohaku. My traps didn't catch anything this afternoon," Chrome grumbled. "Maybe I should look for other places for them…"

A while later, at the shed of science, Senku exchanged his full pouches for empty ones, put several items in a sack made of boar hide, and started the journey to his destination, which he reached eventually after much huffing and puffing. He had only just set down his sack and was about to sit down on the ground near a familiar pile of stones when he heard the voice of the person he had intended to wait for.

"Senku?"

"Ah, Suika, you're here," he said, without turning around. Instead, he picked up the sack again and started walking. "Come here for a minute…"

And that was the day that Senku taught Suika how to roast sunflower seeds.

* * *

After carrying the stones to a nearby area with less greenery, Senku started a low, but wide, fire, and, with Suika's help, dropped the stones in one by one and waited for them to heat up. Then he carefully balanced the clay plate he had brought on top of the stones, and when that had heated up as well, he asked Suika to take the large pouch from inside the sack and pour the sunflower seeds onto the clay plate.

While roasting the seeds, Senku took care of the clay plate, the rocks, and the fire while Suika fetched kindling for the flames when the heat was too low, or water from a nearby river using the bamboo containers Senku had brought in case the heat was too high.

When the seeds were ready, the two of them sat in the grass and used large pebbles to crack the hard shells open to reach the crunchy treats inside. Things went slowly at first, but Suika became faster in the process as she learned the best ways to open them.

_Suika shouldn't be hungry; it isn't logical to work and work without taking care of yourself,_ Senku mused as he cracked sunflower seed shells next to Suika. _Sunflower seeds are simple to prepare, and with more food and a wider variety of vitamins and minerals, she'll be a more productive member of the kingdom of science._

"This is fun!" squealed Suika happily as she opened another sunflower seed shell. "But… the flowers we used looked old, Senku. Why didn't you choose younger ones?"

Senku gestured to the discarded stalks next to him.

"I didn't choose them today; I got them over a week ago. If you want to roast seeds like we just did, Suika, you can't use fresh sunflowers because the seeds won't ready yet. You can only use sunflowers that are at the end of their biological life cycle."

"Bio… huh?" she asked, confused.

"A biological life cycle," Senku explained, "is the series of changes that organisms – in this case, plants like sunflowers – go through while they're alive. And if you want to eat sunflower seeds on a regular basis, you need to know each time how many seeds you want to get and how many flowers you'll need, because like watermelons, sunflowers are monocarpic plants."

After absorbing the information, Suika said, "So… we can only use wilted sunflowers, right?" When she saw Senku nod, she asked, "What does monocarpic mean?"

"Monocarpic plants are plants that…"

* * *

After several warm, lazy hours sitting in the sun while surrounded by bright yellow sunflowers, chatting about the village, the nearby forests and mountains, Suika's dog, the best ways to choose sunflowers for future seed roasting, and other subjects, Senku and Suika's supply of roasted sunflower seeds dwindled down to nothing.

Senku had never seen anybody look both so delighted and so utterly despondent at the same time – and with a watermelon hat, at that.

"This was so, so delicious! But… um…" Suika said sadly, "…it looks like Suika finished it all. Now we don't have any to share with Kohaku and Chrome…" She gave a tearful sniffle. "I'm sorry, Senku…"

Senku gave a careless wave. "Don't worry. We can always come back."

And they did.

* * *

_The first time had been a genuine accident, but after that, for years, Suika would always playfully finish all the sunflower seeds at the end of their occasional sunflower afternoons together, prompting Senku to say with amusement that they could always make more next time._

_One day, they made so much that there really_ **were** _enough seeds to take back and share with the others, and Suika was worried their sunflower field visits would come to an end…_

_…until Senku reached out and stuffed all the leftover seeds in his mouth, claiming that he needed energy for the long walk back to the village._

_Suika giggled and told him that they could always make more next time._

**Notes for the Chapter:**

> \---
> 
> **I. My personal comments:** I wanted to include this chapter because both platonic and romantic love change the way you see people; the way you see life. Kohaku won't be seen in every chapter, but every time Senku feels affection for his friends and concern for the people under his protection, he grows as a person, and takes one step closer in learning how to love her :) Not only that, but Senku and Suika like and trust each other very much in the manga and anime, and I like to think that this was how they formed their special connection :)
> 
> **II. Question of the day:** Can you find the small clue that let Senku know that Suika would visit the sunflower field that day? :D
> 
> **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Eleven ("Sunflower Treat")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
> \---
> 
> **IV. My responses to your comments:**
> 
> 01\. (25/09/2020) (C01) dippitylovelygirl: Aww! Don't worry; he'll grow closer to the others! :)
> 
> \---


	12. (S01 E08g) Iron Sand (Days 29-42)

**Chapter Twelve: (S01 E08g) Iron Sand (Days 29-42)**

The fifth week they collected iron sand, Senku realized how difficult masonry was.

Designing an ironmaking furnace had not been a problem, and because of Chrome's familiarity with the surrounding area, finding boulders of the right type of rock – sandstone had been used in ancient times for building homes and public structures, which meant it was certainly sturdy enough to use to construct a furnace – had not been a problem either.

The problem was how to turn large car-sized boulders into several useable blocks of stone.

It was all very well and good to try and use rocks to smash other rocks, but the problem with that was that the pieces ended up being too small. If the goal had been to get rock fragments the size of limes or apples, the job would have already been half done. But because Senku knew they needed blocks of stone about the size of shoeboxes so that they would be strong enough, they needed to use a different method to get the pieces they needed.

Eventually, they decided to work on the smaller boulders first. After finding one that was the size of a third of a car, Senku and Chrome went to work. Instead of using a large, heavy rock to smash the boulder from above, they used stone tools and watermelon-sized rocks to break the boulder from the side with the intention of chipping away at it until it was the proper size.

It worked.

But it was inefficient.

Using that method, it took Senku and Chrome a few hours to shape a single block – and they needed many, many blocks to build the furnace. However, they couldn't focus on that task alone because they also needed to collect iron sand. If they didn't have enough of it, the furnace would be useless.

Not only that, but that manner of extracting single stone blocks was wasteful. They ended up making only single blocks from boulders that could have yielded three or four. Unfortunately, the lime-sized and apple-sized pieces that broke off would be too small to use to construct the furnace because their small mass wouldn't be able to support the weight of the rocks that would be placed above them, even with solidifying clay to hold everything in place.

During the week, Senku and Chrome extracted a few sandstone blocks in the morning and early afternoon using this inefficient method before cooling off in the river and collecting iron sand with Kohaku and Suika for the rest of the day.

There was always more iron sand to gather.

* * *

The sixth week they collected iron sand, Senku found out how stupidly strong – and fast – Kohaku was.

"Senku? Chrome? What are you doing here?"

Kohaku, who was holding a pot full of hot spring water, came out from the trees.

"Ah, looking at stones again, aren't you? You're really similar to each other…"

"Not just looking," said Senku, gesturing to the boulder beside him. "We need to make several blocks this size…" he gestured with his hands, "from this rock."

Chrome continued Senku's train of thought.

"The problem is that it takes so long to break one and make it the proper size…" he complained.

"Oh?" mused Kohaku, putting down her pot near the boulder and reaching behind her to take out her weapons. "Let me try…"

And, as Senku and Chrome watched, her hands disappeared in a flurry of strikes, each one faster than the last, and as Kohaku's weapons made swift contact with the boulder, several large pieces broke off and fell at her feet.

When she was finished, she stepped back.

"How's that?"

"If you had used raw power," commented Senku, "the edges would be a lot rougher, and there would be more small pieces and more sand on the ground…"

After kneeling down, he used his fingers to feel the edges of sandstone block closest to him.

"…but because of your speed, the pressure on the boulder didn't last long, so the stones stayed mostly intact… Now we have the building blocks we need!"

She was about to reply when she heard Chrome.

"Yeah! Now we can get rocks and make our furnace!" Chrome exclaimed happily. "You're incredible, Kohaku… just as strong as a gorilla!"

And, before Senku could blink, Chrome had a pile of painful-looking lumps on his head.

_She really **is** fast._

"Stop calling me a gorilla!" growled Kohaku.

"Oww…" moaned Chrome, rubbing the top of his head. "Kohaku, you didn't have to hit that hard…"

"Anyway," she said, giving Chrome a warning glance before turning to Senku, "do you want me to do that again to any of these other boulders?"

Senku looked at the sandstone blocks she had already created from smashing a single massive rock to pieces.

"Nah, not today… Chrome and I will carry these to the camp and make measurements. We might need you to do this again tomorrow, though."

Nodding, she said, "Alright. Then I better get this to Ruri-nee before it gets cold…"

With that, Kohaku strapped her knives to her back, bent slightly to lift up her large earthenware pot of hot spring water, and hummed a light tune as she effortlessly carried the hot water in the direction of the village.

* * *

_Someday, far into the future, he would talk to her about a different rock that she had also smashed to pieces for him._

_"Taking me to Ishigami Village, getting out Byakuya's glass record…" Senku spoke some more, then paused. "You're always the one doing it, aren't you?"_

_"Doing what?" asked Kohaku._

_"Bringing that old man back home to me."_

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** When I thought about it, I realized that Kohaku does very special things for Senku that are DIRECTLY related to his father O.O And as for how Senku knew that he could trust Kohaku with something as precious as his father's concrete gravestone, I like to think it was because of something like this - that it was because Senku and the others learned things about each other as they became friends during the weeks and weeks they spent gathering iron sand together :)
> 
>  **II. Question of the day:** What do you think of Senku and Kohaku's future conversation? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Twelve ("Iron Sand, Days 29-42")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
> **IV. My responses to your comments:** (Oops! Looks like there are no comment replies this time. Maybe next time? :P)
> 
> \---


	13. (S01 E08h) Iron Sand (Days 43-56)

**Chapter Thirteen: (S01 E08h) Iron Sand (Days 43-56)**

The seventh week they collected iron sand, Senku, Chrome, Kohaku, and Suika worked with different types of materials.

The first few days were spent smashing and smoothing down enough sandstone rocks to make into large bricks to build the furnace they would need to make iron sand. Kohaku's smashing prowess made things proceed much faster, although because she took some time each day to bring hot spring water to her sister, the process of bringing the stones back to the camp depended on Senku and Chrome's strength and physical stamina.

And whenever anything depended on Senku's strength and physical stamina, it wasn't going to be finished very quickly.

Eventually, they had the stones they needed where they needed them, and after Suika showed Senku where he could find many tall, sturdy bamboo plants, he enlisted Chrome and Kohaku's help in cutting some down and bringing them back. While Kohaku could carry several poles by herself, Senku and Chrome had to resort to teaming up to be able to carry two or three at a time. But because they didn't need that many, one trip was sufficient.

After piling the bamboo beside the sandstone bricks, it was time to make the mortar that would hold the bricks of the furnace together.

_I wonder if Taiju still remembers that you can make four things from seashells?_

Senku planned to use both mortar and solidifying clay – the mortar because it worked as a binding agent, and clay because the bricks weren't uniform and needed something more solid than mortar to even out their edges and fill in gaps, like placing plaster in a hole in a wall. Once he was able to describe to Suika what he needed, she set off with an empty pot to get some while Senku, Chrome, and Kohaku worked on crushing the seashells they had gathered three weeks ago.

Senku had crushed some shells himself the week they were gathered to make a few bars of soap – partly for all of them to use, and partly to satisfy Chrome's rabid curiosity. However, the majority of the shells had stayed in the baskets they had been gathered in… until now.

The three set to work grinding shells with stone and wooden tools, the process taking a while because of the amount they had. Suika had returned from gathering clay and was finished preparing the large mushrooms she had also gathered for the evening meal by the time they were finished.

Because each day's work had to be accompanied by hunting, or fishing, or both, as well as gathering iron sand, the four of them were kept busy, but they accomplished a good amount of work by the end of the week.

* * *

The eighth week they collected iron sand was the final week they collected iron sand.

Their previous efforts had resulting in their obtaining sandstone bricks, bamboo, clay, and mortar from shells. It was time to put those things together to build the furnace, so Senku and Chrome got to work.

After Senku re-sketched the furnace's blueprint on a new piece of flat bark, they began to construct the furnace. The first thing they did was dig, because even in the modern era, homes and buildings that used stone and cement needed a foundation beneath surface level so that they would hold true against earthquakes and storms.

When they had dug a sufficiently deep circular trench, Suika volunteered to use the clay she had gathered to patch up the sandstone blocks that had cracks and holes, and Senku let her get to it as he, Chrome, and Kohaku began the process of laying down bricks and coating them with mortar.

He noticed Suika's watermelon hat touching the stone as she peered carefully at the bricks very closely, to the point that she surely must have been cross-eyed how close her eyes were to the object she was looking at.

 _Is Suika looking that closely because she can't see the block very well?_ Senku wondered. _It's already right in front of her, though…_

As he watched, Senku noticed that she took an unusually long amount of time to inspect each sandstone brick, tilting her head at all angles and looking as closely as her watermelon hat could allow her to look before deciding whether a particular brick needed solidifying clay or not. When clay was required, she took a wet handful with one hand and used the other to feel the brick with her fingers, still looking for imperfections, as if…

 _…As if she doesn't trust her own eyesight,_ he mused.

Because the clay needed time to dry, Senku decided that they would first use the bricks that didn't require it, and then go gather iron sand at the river while it hardened. After they had rested, Senku and Chrome would go back to building the furnace, Kohaku would leave for the hot springs – for this week, she had decided to temporarily change her routine to bringing Ruri hot spring water in the evenings instead of mornings – and Suika would usually stay behind to gather more iron sand at the river.

Most of the week had passed by the time they finished building the furnace, and the lack of rain in the time that followed allowed it to bake in the sun and harden, resulting in a solid ironmaking furnace. When it was complete, they spent the last two days gathering iron sand all day. Without anything else to do now that the furnace was complete, it was strangely reminiscent of their first week of collecting iron sand, with all four of them staying close to each other for most of the day.

And, at the end of the eighth week, Senku, Chrome, Kohaku, and Suika completely filled the pot with iron sand.

They finally had all the iron sand they needed.

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** They spent eight long weeks gathering enough iron sand for... two magnets O.o To recap, during these past fifty-four days, they acquired iron sand, animal hide leather, pouches, shells, sandstone blocks, bamboo, mortar, solidifying clay, a furnace... and sunflower seeds :D
> 
>  **II. Question of the day:** How do you feel about the end of their iron sand collecting marathon? :)
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Thirteen ("Iron Sand, Days 43-56")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
> \---
> 
> **IV. My responses to your comments:**
> 
> 02\. (19/10/2020) (C12) PoisonPen37: I'm so glad to hear that; thank you! :D
> 
> \---


	14. (S01 E08i) Detective Work

**Chapter Fourteen: (S01 E08i) Detective Work**

Having known in advance that burning wood alone wouldn't be enough to reach the temperature they would need to melt the iron sand, Senku used bamboo and animal leather to make primitive bellows to help them pump oxygen into the furnace.

They started out fine, using the bellows together, but even though they were only opening and closing the bellows, the pace at which they all had to do it was gruelling, and Senku's arms started to get sore with the amount of effort he was exerting.

And ironically, despite doing all this to provide the furnace with air, Senku was running low on it himself. As he was putting all his strength into the bellows, he had little energy to spare to take in more than small gasps of air, which left him panting as the work continued.

With four people working, it should have taken twenty to thirty hours... but Senku hadn't accounted for how exhausting it would be to keep up the pace. Suika was the first to collapse after three hours, with Senku following her another three hours later. Chrome put up a good effort for an additional hour, but in the end, it was Kohaku who lasted the longest, pumping oxygen two hours longer than everybody else before she slumped over the ground in exhaustion with the others.

It was at that point that Senku said they needed additional manpower, which meant finding out what people wanted and seeing if science could give it to them. Suika said she would go investigate, which was fine with Senku, but then...

"Suika can go anywhere in the village without people knowing because Suika can turn into a suika!" she exclaimed, before spinning... into her watermelon?

Blinking, Senku mentally calculated the volume of the watermelon, and immediately concluded that there was no way a young girl could fit inside... but since it had happened right in front of him, it wasn't something he could deny, either.

It looked like while the modern era had surprises for the stone world, the stone world had surprises for the modern era, too.

* * *

As they munched on grilled fish around an open fire, Suika told them about her mission. Apparently, she had investigated the village all day and asked people if they wanted anything. She mentioned three women, and if she had grouped them together, they might want the same thing. If Senku could get it for them, that would already almost double the kingdom of science's manpower.

"What these three want most is..."

"I sure hope it's something that science can make in this era..." muttered Senku.

Some things, like soap, could be created even in the stone world. Other things needed more modern technology in order to be made...

"Boyfriends!"

"Of course it had to be something absolutely impossible for science!"

...and some things, like _**boyfriends,**_ were things you couldn't make with stone world science **_or_** modern era science.

"Did they say anything else, Suika?" Senku asked.

"Yup! Garnet said she wants a strong man, Sapphire said she wants a hottie, and Ruby said that she wants somebody who will dote on her."

 _This is inconvenient,_ Senku thought to himself. _They're the first people I've heard about, but what they're looking for is impossible for me to come up with. I already know that science won't be able to give them what they want. They're no way that science can give them boyfriends._

"Hah!" Kohaku laughed. "From the way I look at it..."

_The first one wants a strong man... and physical strength isn't exactly the specialty of the kingdom of science. The second one wants a handsome man, but that isn't something that can be measured, except maybe by facial symmetry or by The Golden Ratio of Beauty Phi. And it's not like I can go around measuring people's faces for her._

"...you're kind of an attractive man, Senku."

_So those two clearly aren't options. And the third one... she wants somebody who will dote on her? That's pretty general. Does she want somebody who'll pay her a lot of attention? That'll take time, and besides physical strength, time isn't something that the kingdom of science has a lot of, either... well, we have time for important things, like gathering iron sand to create magnets, but not for relationships._

"I don't think you're the type of hottie..."

_After eight weeks of work, we finally have all the iron sand we need, but our plan to make them into magnets depends on what the villagers want. If we can't find a way to make them happy, we won't be able to make iron, which means no magnets, which means no electricity, which means no sulfa drug. It all starts with iron, and that means getting enough manpower to melt the iron sand that we've gathered. We need people._

"...that Sapphire was talking about though."

_Then again, even if they were talking about boyfriends, maybe we can give them something else. Out of these three, the "somebody who will dote on me" girl is the one we have the best chance with right now. Parents dote on their kids, so doting depends on what you do for the person. If we can figure out exactly what she wants, we may be able to make a plan, and get their help to make iron. We'll need as many people as possible to melt the iron sand._

After coming back to reality, Senku nodded decisively.

"The "somebody who will dote on me" girl will be our shot," he declared to Suika. "What does she want?"

**Notes for the Chapter:**

> \---
> 
>  **I. My personal comments:** They finally have enough iron sand, but not the manpower they need to melt it! And... poor, oblivious Senku... XD He's very focused on iron sand and manpower at the moment :D
> 
>  **II. Question of the day:** What do you think of Senku's priorities? XD
> 
>  **III. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Fourteen ("Detective Work")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
> \---
> 
> **IV. My responses to your comments:**
> 
> 06\. (05/11/2020) (C10) Nefres: Senku cares so much about people, but he's also cautious about trusting them... :O
> 
> 05\. (05/11/2020) (C09) Nefres: I like to think that Chrome and Kohaku have their own special connection! :)
> 
> 04\. (31/10/2020) (C03) mistu: Thank you so much! :D I love writing about Senku and Kohaku! ^_^
> 
> 03\. (30/10/2020) (C13) PoisonPen37: Senku is very observant! :)
> 
> \---


	15. (S01 E08j) Foxtail Ramen

**Chapter Fifteen: (S01 E08j) Foxtail Ramen**

The delicious aroma of the warm ramen wafted in the air, making everybody's mouths water.

Last night, after seeing Suika use a foxtail stalk to play with her dog, Senku had the idea to make ramen out of foxtail millet.

With Kohaku's slashing prowess, getting enough foxtail grass the next day has been no problem at all. The beating of the stalks to extract the grains had taken far longer. Seeing them hitting the foxtail grass had horrified Chalk, who made things difficult for Senku because of it, at least at first… but that was another story.

Next came the process of removing the little bits of inedible fluff that remained in the grains. Senku found out that despite his and Chrome's relatively close battle power rankings – or at least, Kohaku's estimates – Chrome had an easier time carrying a large pot of water than Senku.

As the man had apparently spent his entire childhood carrying rocks, while Senku had spent his carrying books, Chrome's greater stamina – although he **_was_** tired after setting down the pot of water – wasn't too much of a surprise.

"Now that we have these grains," Senku said, holding up a handful of the green foxtail millet, "all we need to do is turn them into flour, and we'll be able to make the noodles!"

Chrome, Kohaku, and Suika looked at him in confusion.

"What's flour?"

"What are noodles?"

"And how do we make flour into noodles?"

* * *

It turned out that after they acquired the millet, they needed to set aside time to create proper tools to turn it into flour, which involved shaping a few large flat stones close to each other and likewise making small flat stones with which to grind the foxtail millet to get flour.

And later, after they acquired flour and noodles and eventually made ramen – hence the mouthwatering aroma – Chrome volunteered to eat the mysterious new food, which wasn't a surprise, as he had been eating all sorts of roots and leaves and plants for years to look for something that could cure Ruri.

"IT'S SOOOOO GOOOOOD!"

Considering how delicious ramen was, Senku understood Chrome's enthusiastic reaction to his very first time trying it. What he **_didn't_** understand was how he could almost see yellow light shooting out of Chrome's eyes, as if his feelings for the bowl of noodles couldn't be contained and had to manifest themselves as laser beams.

He blinked.

_I must just be imagining things._

After Chrome's unmistakable recommendation, Kohaku and Suika tried their ramen as well – Kohaku, who was more cautious, tried a single noodle at first.

If the foxtail millet of the stone age ended up being poisonous for some reason, it would probably be useful to have one person less affected by it than the rest…

"I can't believe that food like this actually exists in this world!"

…although from the way she tore into her ramen after that, it probably wouldn't be Kohaku.

Meanwhile, Suika had no problem with slurping up several noodles at once… and when she discovered the chewy texture of the noodles for herself, she seemed to keep on slurping without stopping. Ramen was very different from sunflower seeds, but it looked like both had met her approval.

Senku, satisfied by their extremely positive reactions, tasted his own ramen. Unfortunately, the food they had worked hard to make together did not meet his expectations.

As he chewed, he struggled to keep his mouth closed to prevent himself from spitting out the crumbly, disgusting ramen.

_Why is this so bitter?! It tastes like medicine!_

* * *

Minutes later, while Senku still hadn't finished his single bowl, the others made quick work of theirs. Chrome, who had started first, also finished first, and got himself a second serving almost immediately.

After being helped by Kohaku refill her bowl, Suika took a noodle and attempted to feed Chalk, who approved of the gesture. The small dog gobbled up the short noodle in record time before silently pleading with the watermelon girl for another. Suika, of course, obliged.

Kohaku served herself some more ramen as well before sitting next to Senku, who was watching in amusement as Chrome seemed to attempt to finish his second bowl even more quickly than his first.

"You're not eating, Senku?"

Senku looked down at his own bowl, which, aside from the few horrible mouthfuls he managed earlier, was mostly untouched.

If he had been served such awful ramen in the modern era, he would have refused to eat another bite… but the memories of near-starvation during his six months of solitude, before he revived Taiju, were at the back of Senku's mind, and he couldn't justify throwing away food for any reason.

Peering into his bowl, he frowned critically.

 _This is nothing like the ramen Byakuya and I used to eat,_ he thought to himself, _but it'll do._

"Byakuya?" asked Kohaku curiously.

_Oh, I said that out loud?_

"Who's Byakuya? Is he a…" she paused, then pronounced the unfamiliar word carefully, "…a scientist, like you?"

A pause.

In his mind's eye, Senku saw water, as well as something that he had created in the past to help his father: the swimming electrodes that helped Byakuya pass his astronaut exam and go to outer space.

_I'll follow that old man. I just need more time._

"No," he said simply as he dipped his makeshift chopsticks into the most awful – yet ironically, also the most delicious – ramen on the face of the stone world. "I'm a scientist, like him."

As he ate, Senku felt the weight of his ramen bowl.

It was heavy.

**Notes for the Chapter:**

> \---
> 
>  **I. Question of the day:** How do you feel about his conversation with Kohaku about his father? :)
> 
>  **II. A tiny request:** Thank you for reading my fanfic! :D If you've read this far, I hope you'll consider taking an extra minute to leave a comment for Chapter Fifteen ("Foxtail Ramen")? :D Comments really mean a lot to me as a fanfiction writer, and all kinds of positive, negative, and/or constructive comments are very welcome! ^_^ Even if it's the year 5738 or something, I would love to hear your thoughts on this chapter! :D (By the way, I'm "fireflyhwufanficwrit" on Reddit and "firefly-hwufanficwriterrrrr" on Tumblr :D)
> 
> \---
> 
> **III. My responses to your comments:**
> 
> 14\. (15/01/2021) (C14) AC_2_Lex: Thanks! :)
> 
> 13\. (17/12/2020) (C07) alightintheshadows: He sees people for what they truly are :D Thank you very much for all of your comments! ^_^
> 
> 12\. (17/12/2020) (C06) alightintheshadows: She knew what Chrome was like XD
> 
> 11\. (16/12/2020) (C05) alightintheshadows: They've both been working really hard for Ruri's sake :'(
> 
> 10\. (16/12/2020) (C04) alightintheshadows: This happened in the manga, actually... too bad they didn't include it in the anime!
> 
> 09\. (16/12/2020) (C03) alightintheshadows: That chapter showed us that Kinro is more formidable than a bubble, which is important information XD
> 
> 08\. (16/12/2020) (C02) alightintheshadows: It must have been fascinating for Senku to meet somebody who wasn't from the modern era! :)
> 
> 07\. (16/12/2020) (C01) alightintheshadows: Ruri really loves Kohaku, so she's happy that her little sister found friends! :D Thank you so much! :D
> 
> \---


End file.
